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Main Boards => The Bowyer's Bench => Topic started by: scottm on January 02, 2012, 05:51:00 PM

Title: Bow Oven ?
Post by: scottm on January 02, 2012, 05:51:00 PM
Ive built a bow oven to bake an all bamboo bow im trying to build.The oven is 72"x12"x24".Its built out of 1/2"ply wood.I put in 4 100watt bulbs with a 180 deg. thermostat.In a 60 deg.shop how long would you estimate it should take it to get to temperature?It seemd to jump to 120 deg. right away then slow way down.Is this normal? Or am i going to have to add some insulation?Thanks Scott
Title: Re: Bow Oven ?
Post by: scottm on January 02, 2012, 06:08:00 PM
Update:Its ben 1.5 hours.Its up to 130 deg. at the top.The box doesent even feel warm on the outside.I know plywood has a low R value but i dont think im loosing much heat.But ive ben wrong before.
Title: Re: Bow Oven ?
Post by: Roy from Pa on January 02, 2012, 06:10:00 PM
My oven is about the same size, and three, 200 watt bulbs only take it too 143 degrees. You might want to try a couple 200 watters in there.
Title: Re: Bow Oven ?
Post by: Glunt on January 02, 2012, 06:10:00 PM
I couldn't get mine to 180 without insulation.
Title: Re: Bow Oven ?
Post by: dmikeyj on January 02, 2012, 06:20:00 PM
+1 on the insulation.  I have seen a few that were made from just insulation board, but insulating it will definitely help raise the inside temps...
Title: Re: Bow Oven ?
Post by: JamesV on January 02, 2012, 06:25:00 PM
My box is about the same, lined with tin-foil and I use 8 100 watt bulbs with a small exaust fan to pull the moisture out of the box. 6 bulbs usually will get me to 180 degrees but when extremely cold in an unheated shop it takes 8 bulbs.
Title: Re: Bow Oven ?
Post by: scottm on January 02, 2012, 07:19:00 PM
Thanks fellas.I guess im going to do some revamping.Its ben allmost 3 hours and im not gaining anything.Im glad i tried it before gluing the bow up.Ill let you know how it works out.Thanks again,Scott
Title: Re: Bow Oven ?
Post by: milehi101 on January 02, 2012, 07:22:00 PM
I use 4 200 and can get it to 180 in abour 10 minutes unless it is really cold.
Title: Re: Bow Oven ?
Post by: Living_waters on January 02, 2012, 08:05:00 PM
QuoteOriginally posted by dmikeyj:
+1 on the insulation.  I have seen a few that were made from just insulation board, but insulating it will definitely help raise the inside temps...
Mine has a ply bottom and the rest is 1.5" foam board. I lined the inside with foil and have 2 100 watt bulbs. I use the foil furnace tape and seal the top and it will maintain 180+ in a 40 degree shop.

I used expand foam to glue the foam together then foil taped the corners. It needs a fan though to circulate the heat making it more evenly heated.
Title: Re: Bow Oven ?
Post by: scottm on January 02, 2012, 10:28:00 PM
Well ive insulated it with foil backed 1" insulation board.I had the thermostat mounted to the inside of the top.Put my thermometer in the side about 6 inches from the bottem.It reched 180 at the top in about 30 min. but only 160 near the bottem.So i mounted the thermostat lower in the box.Im going to try again tomorrow after i get some 200 watt bulbs and maby a fan.Thanks,Scott
Title: Re: Bow Oven ?
Post by: kennym on January 02, 2012, 10:39:00 PM
I'd say with 1" insulation and 4 - 200s you should be able to cook pizza AND a bow at the same time Scott!
Title: Re: Bow Oven ?
Post by: scottm on January 02, 2012, 10:44:00 PM
Sounds great kenny!Two of my favorite things!
Title: Re: Bow Oven ?
Post by: Roy from Pa on January 02, 2012, 10:51:00 PM
Scott, just occurred to me that you want to bake an all Bamboo Bow. I may be wrong here, however I think 180 degrees would dry out the boo way too much. Making it very brittle. All you need is for the glue to dry. Are you using URAC 185 for the glue up? If so, it will dry at 70 degrees.
Title: Re: Bow Oven ?
Post by: Living_waters on January 03, 2012, 08:21:00 AM
URAC will dry in 6 hours at 70 degrees or 1 hour at 100 degrees in an unstressed joint. In a stressed joint I like 100 degrees for 24 hours then let it rest for 48. I believe nelson paint says 100 is the max you want for curing.
Title: Re: Bow Oven ?
Post by: tenbrook on January 03, 2012, 08:40:00 AM
4 x 200w is the ticket.

Gets me to 180 within and hour depending on the weather.

Tenbrook
Title: Re: Bow Oven ?
Post by: eflanders on January 03, 2012, 09:42:00 AM
175' f  I think is the release point for URAC. If using Urac, better check with Nelsons to be sure of the proper temp to cure!
Title: Re: Bow Oven ?
Post by: scottm on January 03, 2012, 05:49:00 PM
Ive got some Urac.And have used it in the past.I was going to try epoxy for this project.It says to bake it at 165-190 deg.Would i be better off to use Urac.Thanks Scott
Title: Re: Bow Oven ?
Post by: eflanders on January 03, 2012, 05:55:00 PM
If the bow you are building is all-wood, Urac is easier to use and clean-up.
Title: Re: Bow Oven ?
Post by: Crooked Stic on January 03, 2012, 07:26:00 PM
You might try throwing a blanket over it to maintain the heat.
Title: Re: Bow Oven ?
Post by: Jermcramp1 on January 04, 2012, 05:08:00 PM
is it too late to ask for pics of the bow? I have a bow idea of all bamboo and want to see yours....
Title: Re: Bow Oven ?
Post by: mmgrode on January 05, 2012, 12:15:00 PM
I've used both urac and smooth on for bbo's.  No question smooth-on is superior.